| Optical fiber is produced by drawing it from a large quartzrod, a preform in high temperature of appx. 2000 degrees Celsius. The preform diameter can be 18...100 mm in diameter and appx 1 meter in lenght. Fiber is drawn from the preform in a ratio of 1:500 when the lenght of the fiber will be this ratio squared >> 500*500 m = 250 000 m. |
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Preform and induction furnace
The glass of optical fiber is very thin, therefore it is also fragile. Therefore the glass fiber is coated to gain resistance to mechanical stress with liquid acrylates . The liquid coating is applied to the fiber with dies and cured hard with powerful UV-lamps. The coating cures to cover the fragile fiber. |
Coating applicator |
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Set of UV-lamps
The coating acrylates cures immediately, and allows some mechanical stress on the fiber. The fiber can now be spooled on a motherspool, with capacity of appx. 250 kms.
The fiber is produced by the fiber drawing operator, who controls the drawing tower from line control cabinet. |
Line control TW1 |
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| Line control TW2 |
Fiber Take-up motherspool
The drawn fiber will have to pass several tests before it is shipped to customer. First test will be mechanical proof test. This test assures the tensile strenght of the fiber. This will assure the fiber good resistivity to mechanical stress the fiber might be exposed to in its lifetime. |
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Fiber prooftesting
The optical fiber must meet strict geometrical tolerances to couple to other fibers, or receivers, transmitters with as low attennuation as possible. Every spool of fibers has been tested twice, beginning and the end of the fiber, through geomtery tests. |
Fiber geometry testing
During propagation through optical fiber a pulse of light is attennuated, despite purest material of the fiber. This attennuation and other properties that affect the propagation of the pulses will be measured and tested, so the overall data-transfer properties can be monitored. |
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Measuring the pulse propagation characteristics
Along attennuation chromatic and polarization mode dispersion is monitored. |
Chromatic and polarization mode dispersion measurement
Also the coating properties that affect to pulse propagation is measured. Micro- and macrobending losses give information on how well the coating protects the fiber against mechanical stress. |
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| Fiber micro- and macrobending equipment |
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